European trees (Chamaecyparis lawsoniana) tolerate USDA Hardiness zones 6-9. Here is a link of the USDA hardiness map. You can click on your state and see what zone you live in: http://planthardiness.ars.usda.gov/PHZMWeb/# .
If you live in a colder zone than 6, we suggest to bring it inside when the temperature gets cold. If you can plant it outside, keep in mind that they get to be about 15 feet tall and 5 feet wide. They prefer well drained soil and should not be kept soggy wet all of the time. They like either full sun or partial shade. If you are within the correct zones, we suggest you plant it outside as soon as possible. You will see it perform so much better outside and your tree will be able to get more sunlight and nutrients from the soil.